Heat and Mass Transfer The unit of overall coefficient of heat transfer is kcal/m² kcal/m² hr °C kcal/m hr °C kcal/hr °C kcal/m² kcal/m² hr °C kcal/m hr °C kcal/hr °C ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal diffusivity of a substance is Inversely proportional to density of substance All of these Inversely proportional to specific heat Directly proportional to the thermal conductivity Inversely proportional to density of substance All of these Inversely proportional to specific heat Directly proportional to the thermal conductivity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The heat transfer by conduction through a thick cylinder (Q) is given by (where T₁ = Higher temperature, T₂ = Lower temperature, r₁ = Inside radius, r₂ = Outside radius, l = Length of cylinder, and k = Thermal conductivity) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following is a case of steady state heat transfer? None of these Air preheaters Heating of building in winter I.C. engine None of these Air preheaters Heating of building in winter I.C. engine ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The rate of energy emission from unit surface area through unit solid angle, along a normal to the surface, is known as Transmissivity Emissivity Intensity of radiation Reflectivity Transmissivity Emissivity Intensity of radiation Reflectivity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Radiation is the process of heat transfer in which heat flows from a ________, in a straight line, without affecting the intervening medium. Cold body to hot body Larger body to smaller body Smaller body to larger body Hot body to cold body Cold body to hot body Larger body to smaller body Smaller body to larger body Hot body to cold body ANSWER DOWNLOAD EXAMIANS APP
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